Electrical current based temperature sensor and temperature information digitizer

Abstract

The described technology is generally directed towards an electrical current based temperature sensor and temperature information digitizer, referred to herein as a “temperature digitizer”. The temperature digitizer can include a sensor core, a digital to analog converter, a current comparator, and a processor. The processor can be configured to perform multiple current comparisons using the sensor core, digital to analog converter, and current comparator, and the processor can generate a digital code that reflects the results of the multiple current comparisons. The digital code represents the temperature.

What is claimed is: 
     
       1. A temperature digitizer, comprising:
 a sensor core, wherein the sensor core is configured to generate a temperature dependent electrical current and at least one reference electrical current, wherein the temperature dependent electrical current and the at least one reference electrical current originate from a sensing device at the sensor core; 
 a digital to analog converter, coupled to the sensor core, wherein the digital to analog converter is configured to generate a controlled electrical current which is combined with the at least one reference current to generate a modified reference current; 
 a current comparator, wherein the current comparator is configured to perform a comparison of the modified reference current and the temperature dependent electrical current and to generate a binary result of the comparison; and 
 a processor, wherein the processor is configured to:
 record the binary result of the comparison provided by the current comparator; 
 generate a current control output based on the binary result and provide the current control output to the digital to analog converter, wherein the current control output modifies the controlled electrical current generated by the digital to analog converter; 
 repetitively record subsequent binary results and generate subsequent current control outputs to generate a digital code comprising a series of binary results; and 
 output the digital code. 
 
 
     
     
       2. The temperature digitizer of  claim 1 , wherein the sensor core comprises a bipolar junction transistor. 
     
     
       3. The temperature digitizer of  claim 1 , wherein the sensor core is configured to generate two reference electrical currents, and wherein the two reference electrical currents comprise first-order temperature independent electrical current signals. 
     
     
       4. The temperature digitizer of  claim 3 , wherein the controlled electrical current is adjusted based on a first of the two reference electrical currents, and wherein the controlled electrical current is combined with a second of the two reference electrical currents to generate the modified reference current. 
     
     
       5. The temperature digitizer of  claim 1 , wherein the digital code comprises an at least eight bit digital code. 
     
     
       6. The temperature digitizer of  claim 5 , wherein the processor is further configured to repetitively generate subsequent digital codes and average the digital code and the subsequent digital codes to identify an at least eleven bit digital code, and wherein the digital code output by the processor comprises the eleven bit digital code. 
     
     
       7. The temperature digitizer of  claim 1 , wherein the current control output based on the binary result is calculated based on the binary result and a successive approximation algorithm. 
     
     
       8. The temperature digitizer of  claim 1 , wherein the processor comprises a successive approximation register logic unit. 
     
     
       9. The temperature digitizer of  claim 1 , wherein the digital to analog converter comprises an eight bit current steering digital to analog converter. 
     
     
       10. A method to generate digitized temperature data, comprising:
 generating a temperature dependent electrical current and at least one reference electrical current with a sensor core, wherein the temperature dependent electrical current and the at least one reference electrical current originate from a sensing device at the sensor core; 
 generating, with a digital to analog converter, coupled to the sensor core, a controlled electrical current which is combined with the at least one reference current to generate a modified reference current; 
 performing, with a current comparator, a comparison of the modified reference current and the temperature dependent electrical current to generate a binary result of the comparison; 
 recording, with a processor, the binary result of the comparison; 
 generating a current control output based on the binary result to provide the current control output to the digital to analog converter, wherein the current control output modifies the controlled electrical current; 
 repetitively recording subsequent binary results and generating subsequent current control outputs to generate a digital code comprising a series of binary results; and 
 outputting the digital code. 
 
     
     
       11. The method to generate digitized temperature data of  claim 10 , wherein a bipolar junction transistor is used to generate the temperature dependent electrical current and the at least one reference electrical current. 
     
     
       12. The method to generate digitized temperature data of  claim 10 , wherein an eight bit current steering digital to analog converter is used to generate the controlled electrical current. 
     
     
       13. The method to generate digitized temperature data of  claim 10 , wherein a current comparator is used to perform the comparison of the modified reference current and the temperature dependent electrical current. 
     
     
       14. The method to generate digitized temperature data of  claim 10 , wherein a successive approximation register logic unit is used to record the binary result of the comparison, generate the current control output based on the binary result, repetitively record the subsequent binary results and generate the subsequent current control outputs, and output the digital code. 
     
     
       15. The method to generate digitized temperature data of  claim 10 , wherein the at least one reference electrical current comprises two reference electrical currents, wherein the controlled electrical current is combined with a second of the two reference electrical currents to generate the modified reference current. 
     
     
       16. The method to generate digitized temperature data of  claim 15 , wherein the two reference electrical currents comprise first-order temperature independent electrical current signals. 
     
     
       17. The method to generate digitized temperature data of  claim 10 , wherein the digital code comprises an at least eight bit digital code. 
     
     
       18. The method to generate digitized temperature data of  claim 10 , further comprising repetitively generating subsequent digital codes and averaging the digital code and the subsequent digital codes to identify an at least eleven bit digital code, and wherein the digital code output comprises the eleven bit digital code. 
     
     
       19. The method to generate digitized temperature data of  claim 10 , wherein generating the current control output based on the binary result comprises calculating the current control output based on the binary result and a successive approximation algorithm.